Heat-treating box



w. HlSMITH.

HEAT TREATING BOX.

APPLICAIION HLED JULY3h19I9.

1,350,421 Patented Aug. 24, 1920.

UNITED STATES PATENT OFFICE.

WILLIAM H. SMITH, OF EAST CLEVELAND, OHIO.

HEAT-TREATING BOX.

Application filed July 31, 1919.

To all whom it may concern:

Be it known that I, WVILLiAM H. SMITH, a citizen of the United States, residing at East Cleveland, in the county of Guyahoga and State of Ohio, have invented a certain new and useful Improvement in I-Ieat-Treating Boxes, of which the following is a full, clear, and exact description, reference being had to the accompanying c rawings.

This invention relates to heat treating boxes and has for its object the provision of a box of such shape as to present a uniform thickness at all points coupled with a minimum of sharp edges. Another object is to provide a box of such shape as will allow free circulation of hot gases thereabout and will stack conveniently in a furnace. Another object is to provide a box which will have a longer life by virtue of its shape. Further and more limited objects of the invention will appear in the detailed description embodied in the specification. In the drawings forming part hereof, Figure 1 is a perspective view of the box with cover removed; 2 is a longitudinal sectional view of the box with cover removed; Fig. 3 is a section on the line 33 of Fig. 2; Fig. 4 represents'the corner of a furnace showing the boxes stacked therein; and Fig. 5 is a modification showing a box adapted for small articles. Describing the various parts by reference numerals, 1 indicates the body of the box, formed of any suitable metal or alloy used for such purposes, and has pref erably integrally formed therewith the feet 2. The lid 3'is shown as bulged as at 4 and formed-with a rib 5, with a slot 6 therein, connecting said bulges, the latter forming a handle for lifting the cover from the box.

In the past it has been the custom to form heat treating boxes of essentially a rectangular shape which presented sharp edges where the sides, ends and bottom met. Upon continuous usage of such boxes, which involves heating and cooling many times, it has been found that they crack wherever there is a sharp edge. This of course renders the box useless and since they are made Specification of Letters Patent.

Patented Aug. 24, 1920.

Serial No. 314,445.

of costly material it forms an important factor in the upkeep.

My heat treating box overcomes this disadvantage by being essentially circular in cross section as shown in Fig. 3 and provided with bulged ends as shown in Figs. 1 and 2 which presents a box without sharp edges and having substantially uniform thickness at all points whereby uniform cooling secured, as a result of which two causes, the tendency toward cracking is much reduced.

The feet 2 serve to keep the box in an upright position and raised slightly from the floor of the furnace. The shape of the box is such, that when stacked they always allow open passages on all sides of the individual box thereby permitting a free circulation of the hot furnace gases through the stack.

From the foregoing it will be seen that I have provided a box of much longer life than the usual types used if made of the same material, or if desirable a cheaper material might be used which will give a life equal to that obtainable with the usual type of box and result in a lower initial cost of the box.

Having thus described my invention, what I claim is:

1. A box of the character described comprising a body portion and a cover therefor, said body portion having a substantially circular cross-section and rounded ends.

2. A box of the character described comprising a body portion cast in a single piece and having its walls everywhere of substantially equal thickness and of externally rounded shape without reentrant angles.

3. A cast metal box for the purpose described having rounded corners and edges and without reentrant angles.

4. A cast metal box for the purpose described having outwardly bulging unbroken surfaced walls with rounded corners and edges.

In testimony whereof, I hereunto ailix my signature.

WILLIAM H. SMITH. 

